爆推快点火模型分析

使用简单的爆推模型估算爆推快点火过程及其结果。首先由ns级主驱动激光直接驱动，形成中心低密度高温热斑，周围为高密度低温主燃料区，两区压力平衡（等压模型）；然后用ps级超短超强激光打入，产生超热电子，其能量在低温主燃料区沉积，主燃料区发生爆炸，一部分向外飞散，一部分向内压缩中心热斑。在这个爆推模型下，热斑体积压缩比为64，中子产率将有极大的提高，相应的中子产额和能量增益得到提高。离子温度因为主燃料区质量过大，提高不大。提高超热电子能量，或者减小低温主燃料区质量，离子温度将会显著提高。不同的初始离子温度对结果

星间激光通信光束微弧度跟瞄性能检测装置的设计原理

基于矢量折射定理，研究了透射光束通过双棱镜实现微弧度量级偏转的设计原理，解决了星间激光通信精跟瞄检测的难题。推导了正交双棱镜实现光束偏转的精确公式，提出以水平张角和垂直张角表达光束视场，并说明了单棱镜实现光束偏转的一般情况。根据设计指标和计算结果确定了棱镜的主要参量，进而对光束的偏转结果进行了数值模拟。最后的实验结果与模拟结果基本一致。结果表明：取棱镜棱角α为4°时，棱镜每旋转1’，透射光束变化约1μrad；分别控制双棱镜在其最小偏向角一侧小角度偏转，可以实现光束在水平方向和垂直方向500μ范围内的精确扫

掺铒高硅氧玻璃光谱性质的研究

应用Judd-Oflet理论计算了新型掺铒高硅氧玻璃中铒离子的强度参量Ωt（t=2，4，6），Ω2=8．15×10^-20,Ω4=1．43×10^-20,Ω6=1．22×10^-20，相比于其他氧化物玻璃，表现出较大的Ω2,6值，反映了铒离子周围的近邻结构不对称性和Er-O键的离子键成分较高．利用McCumber理论计算得到了能级4I13/2→4I15/2跃迁的受激发射截面为σc=O．51pm^2．这种高硅氧玻璃掺铒离子浓度尽管高于石英光纤的掺杂浓度10倍左右，其荧光寿命和量子效率仍达到6．0ms和66．

Colourless adaptively modulated optical OFDM transmitters using SOAs as intensity modulators.

The wavelength dependent transmission performance of adaptively modulated optical OFDM (AMOOFDM) signals is investigated, for the first time, over optical amplification- and chromatic dispersion compensation-free IMDD SMF systems using semiconductor optical amplifiers (SOAs) as intensity modulators. A theoretical SOA model describing both optical gain saturation and gain spectral dynamics is developed, based on which optimum SOA operating conditions are identified for various wavelengths varying in a broad range of 1510 nm- 1590 nm. Results show that, SOA intensity modulators operating at the identified optimum conditions enable the realization of colourless AMOOFDM transmitters within the aforementioned wavelength window. Such transmitters are capable of supporting >30 Gb/s signal transmission over 60 km SMFs.

Synchronous operation control of the Brushless Doubly-Fed Machine

The paper presents a novel vector control structure for the Brushless Doubly-Fed Machine (BDFM) which is derived based on the machine synchronous operation. In fact, the synchronous operation of the BDFM provides an efficient approach for determining the required reference angle in the machine vector control structure. The utilization of such reference angle makes the vector control structure presented in this paper different from and, in fact, more effective than the existing rotor flux and stator flux orientation schemes proposed for the machine. The results of implementing the vector control scheme in simulations confirm the effectiveness of the proposed approach for the BDFM control. © 2010 IEEE.

应用气液两相流模型模拟湖泊风生流

采用了基于两相流理论的三维相间界面计算模型模拟湖泊风生流,并采用交错网格的有限体积法求解。该模型应用于昆明市滇池的风生流模拟,实际计算表明该模型算法程序简单,计算结果合理,能较真实的反映湖泊风生流的流态特征。

绿藻CO_2浓缩机制的研究进展

单细胞绿藻是淡水水体中浮游植物的重要组成部分 ,也是淡水生态系统中主要的初级生产者 ,其在适应外界环境CO2 浓度变化的过程中 ,细胞内形成了一种主动转移无机碳的机制———CO2 浓缩机制(CO2 concentratingmechanism ,CCM ) .该机制能使细胞在核酮糖 2 磷酸羧化氧化酶 (rubisco)固碳位点提高CO2 浓度 ,以增加光合作用和减少光呼吸 .本文综述了这种机制中的无机碳转移模型和不同环境因子 (光、温度、CO2 浓度和营养水平 )对它的调控作用 ,以期促进深入开展浮游植

GENERATION OF PICOSECOND PULSES IN AN INJECTION LASER WITH AN EXTERNAL SELECTIVE RESONATOR.

Pulses of 15 psec duration were generated by an injection laser with an external dispersive resonator operating in the active mode-locking regime. This regime was attained by subjecting the laser diode to a current of high frequency equal to the intermode interval in the external resonator. The duration of the pulses was determined by an autocorrelation method in which the second harmonic was generated in an LiIO//3 crystal.

The refractive nonlinearities of InAs/GaAs quantum dots above-bandgap energy

The third-order optical nonlinear refractive properties of InAs/GaAs quantum dots grown by molecular beam epitaxy have been measured using the reflection Z-scan technique at above-bandgap energy. The nonlinear refractive index and nonlinear absorption index of the InAs/GaAs quantum dots were determined for wavelengths from 740 to 777 nm. The measured results are compared with the nonlinear refractive response of several typical III-V group semiconductor materials. The corresponding mechanisms responsible for the large nonlinear response are discussed.